Biopsy instruments can be used to obtain samples of tissue from the body of a human or other animal. In some circumstances, the biopsy instruments are delivered into the patient's body to retrieve a tissue sample from an internal site. For example, biopsy catheter instruments have been used to retrieve myocardial tissue from within a chamber of the heart. When advancing such a biopsy catheter instrument into the heart, the physician may have difficulty in accessing and maintaining position within a particular heart chamber, such as the right ventricle. In addition, the physician may have difficulty verifying that the catheter tip portion is in fact delivered to the targeted heart chamber.